U.S. patent number 7,096,641 [Application Number 10/768,774] was granted by the patent office on 2006-08-29 for hollow profile.
This patent grant is currently assigned to Hilti Aktiengesellschaft. Invention is credited to Ulrich Birnbaum, Adrian Steingruber, Stefan Unverzagt.
United States Patent |
7,096,641 |
Birnbaum , et al. |
August 29, 2006 |
Hollow profile
Abstract
A hollow profile (1) formed of a flat material (31) having a
width (d) has at least one groove (6.1, 6.2, 7.1, 7.2) provided on
an outer side of at least one of the plurality of walls (2.1, 2.2,
5.1, 5.2) of the profile (1) and having a bottom (8.1, 8.2, 9.1,
9.2) spaced form the outer side by depth (t) and two opposite,
substantially flat side walls (13.1, 13.2, 40.1, 40.2) extending
substantially perpendicular to the bottom (8.1, 8.2, 9.1, 9.2),
with the groove depth (t) of the at least one groove (6.1, 6.2,
7.1, 7.2, 32) amounting to from 0.5 to 2 times of the material
thickness (d) of the flat material (31).
Inventors: |
Birnbaum; Ulrich (Penzing,
DE), Unverzagt; Stefan (Penzing, DE),
Steingruber; Adrian (Graben, DE) |
Assignee: |
Hilti Aktiengesellschaft
(Schaan, LI)
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Family
ID: |
33039224 |
Appl.
No.: |
10/768,774 |
Filed: |
January 30, 2004 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20040237280 A1 |
Dec 2, 2004 |
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Foreign Application Priority Data
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May 19, 2003 [DE] |
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103 22 755 |
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Current U.S.
Class: |
52/282.4;
428/595; 428/596; 428/599; 428/603 |
Current CPC
Class: |
E04C
3/07 (20130101); E04C 2003/0421 (20130101); E04C
2003/043 (20130101); E04C 2003/0465 (20130101); Y10T
403/58 (20150115); Y10T 428/12354 (20150115); Y10T
428/1241 (20150115); Y10T 428/12382 (20150115); Y10T
428/12361 (20150115); Y10T 29/49915 (20150115) |
Current International
Class: |
E04C
3/32 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3513382 |
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Oct 1986 |
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DE |
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19740101 |
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Mar 1999 |
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DE |
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29923482 |
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Nov 2000 |
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DE |
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0906737 |
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Apr 1999 |
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EP |
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1288387 |
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Mar 2003 |
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EP |
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2258502 |
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Aug 1975 |
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FR |
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1605408 |
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Jun 1996 |
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GB |
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Primary Examiner: Zimmerman; John J.
Attorney, Agent or Firm: Abelman, Frayne & Schwab
Claims
What is claimed is:
1. A hollow profile (1) for positioning and guiding a connection
part (26) of an assembly system and formed of a flat material (31);
the hollow profile (1) comprising a plurality of side walls (2.1,
2.2, 5.1, 5.2); at least one groove (6.1, 6.2, 7.1, 7.2) provided
on an outer side of at least one of the plurality of walls (2.1,
2.2, 5.1, 5.2) and having a cross-section corresponding to the
shape of the connection part for longitudinally and laterally
guiding same, the at least one groove having a bottom (8.1, 8.2,
9.1, 9.2) spaced from the outer side of the at least one of the
plurality of walls by a depth (t) that amounts to from 0.5 to 2
times of a thickness of the flat material (31), two opposite,
substantially flat side walls (13.1, 13.2, 40.1, 40.2) extending
substantially perpendicular to the bottom (8.1, 8.2, 9.1, 9.2) and
having an even section (h) extending over a substantial portion of
the groove depth (5), and at least one mounting opening 11.1, 11.2,
12.1, 12.2) formed in the bottom (8.1, 8.2, 9.1, 9.2) of the at
least one groove and through which a fastening element for securing
the connection element to the hollow profile is extendable.
2. A hollow profile according to claim 1, wherein the depth (t) of
the at least one groove (6.1, 6.2, 7.1, 7.2, 32) amounts to less
than 1.5 times of the material thickness (d) of the flat material
(31).
3. A hollow profile according to claim 1, wherein each of the
plurality of side walls (2.1, 2.2, 5.1, 5.2) has at least one
groove provided thereon.
4. A hollow profile according to claim 3, wherein the grooves,
which are provided on the plurality of side walls, have a
substantially same shape.
5. A hollow profile according to claim 1, wherein the flat material
(31) is sheet steel.
6. A hollow profile according to claim 1, wherein the portion of
the groove depths the even section (h) of a flat side wall (13.1,
13.2; 9.1, 9.2) extends over amounts to about 70% of the groove
depth (t).
7. An assembly system, comprising at least one connection part
(26); a hollow profile (1) for positioning and guiding the at least
one connection part; and means (28) for securing the at least one
connection part to the hollow profile, wherein the hollow profile
(1) is formed of a flat material (31) and has a plurality of side
walls (2.1, 2.2, 5.1, 5.2), at least one groove (6.1, 6.2, 7.1,
7.2) provided on an outer side of at least one of the plurality of
walls (2.1, 2.2, 5.1, 5.2) and having a cross-section corresponding
to the shape of the connection part for longitudinally and
laterally guiding same, the at least one groove having a bottom
(8.1, 8.2, 9.1, 9.2) spaced from the outer side of the at least one
of the plurality of walls by a depth (t) that amounts to from 0.5
to 2 times of a thickness of the flat material (31), two opposite,
substantially flat side walls (13.1, 13.2, 40.1, 40.2) extending
substantially perpendicular to the bottom (8.1, 8.2, 9.1, 9.2) and
having an even section (h) extending over a substantial portion of
the groove depth (5), and at least one mounting opening 11.1, 11.2,
12.1, 12.2) formed in the bottom (8.1, 8.2, 9.1, 9.2) of the at
least one groove through which the securing means (28) extends.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a hollow profile formed of a flat
material and having a plurality of side walls and at least one
groove provided on an outer side of at least one of the plurality
of side walls and having a bottom spaced form the outer side by a
predetermined depth and two opposite side walls.
The present invention also relates to a method of forming the
hollow profile.
2. Description of the Prior Art
Generally, a hollow profile, which is formed of a flat material, is
characterized by a small weight while having good static
characteristics. For positioning and guiding of connection, parts,
e.g., add-on parts, a hollow profile of an assembly system is
provided with grooves in which the connection parts are guided.
With add-on components being mounted on a hollow profile, often,
torsional loads act on the hollow profile. Therefore, from a static
point of view, a circumferentially closed hollow profile is
preferred. However, the greater is the depth of the groove the
smaller is the torsional load a hollow profile can withstand.
Therefore, it is desirable to have the groove depth as small as
possible.
As a rule, the size of the inner bending radius of a sheet, which
is bent to 90.degree., corresponds to the thickness of the sheet.
The drawback of this general rule consists in that with a small
groove depths, which are accompanied by small bending radii, it is
impossible to obtain side walls of a groove which would extend
perpendicular to the groove bottom or to the outer side of a
profile. The use of a narrow bending radius corresponding to the
thickness of a flat material is accompanied by upsetting of the
flat material on the inner side of a bent and by stretching of the
flat material on the outer side of the bent. This leads to
formation of fissures and/or reduction of the material
strength.
It is known to form notches before bending at the position of the
inner radius of a material. The formation of notches permits to use
radii as small as the thickness of the flat material. However, this
results in reduction of the cross-section of the material and,
consequently, in reduction of the material strength.
Up to the present, with grooves having a small radius, this problem
was bypassed by forming a groove with side walls extending to the
groove bottom at angle different from 90.degree., e.g., at an angle
of 45.degree.. If a connection part with rectangular bearing
surfaces is loaded sidewise, with such a groove, its guidance in
the longitudinal direction of a profile and the prevention of the
part from rotation is not insured. When the bearing surface of a
connection part is complementary to the shape of a groove, with a
side load acting on the connection part, a force component would be
produced that would extend at an angle to the direction of force
acting on the connection part and that could lift the connection
part out of the groove.
Accordingly, an object of the present invention is to provide a
hollow profile from a flat material with a groove having a small
depth and which would insure an adequate longitudinal and lateral
guidance for a connection part, whereby the absorption of the
torsional stresses would be insured.
Another object of the present invention is to provide a hollow
profile that can be produced simply and economically.
SUMMARY OF THE INVENTION
These and other objects of the present invention, which will become
apparent hereinafter, are achieved by providing a hollow profile of
the type described above and in which the groove depth amounts to
from 0.5 to 2 times of the material thickness of the flat material,
insuring that the side walls would extend substantially
perpendicular to the groove bottom and would be substantially
flat.
With a groove according to the invention, the static characteristic
of a hollow profile made of a flat material are maintained to a
most possible extent, and a reliable longitudinal and lateral
guidance of a connection or add-on part along the hollow profile is
insured. With a connection part having a shape corresponding to the
groove cross-section, the connection part neither rotates nor is
displaced sidewise, i.e., in a direction transverse to the
longitudinal axis of the profile in its mounted condition on the
profile. With the groove bottom being substantially flat, a flat
contact between a connection part and a profile is insured, and the
opposite side walls, which extend to the bottom at an angle
slightly less than 90.degree., are capable to absorb acting, on the
connection part, forces despite a small depth of the groove.
Further, the connection part cannot be lifted off the groove
despite side forces acting on the connection part.
Additionally, e.g., a slide bearing, e.g., of polyethylene can be
arranged in the groove. Such a bearing can be provided, e.g., upon
an arrangement of a part on the hollow profile. The bearing can be
displaceable in the longitudinal direction in order to absorb
stresses generated in the part. Such part can represent a support
or a conducting part such as a tubular conduit or a ventilation
channel.
Preferably, the groove depth of the at least one groove amounts to
less than 1.5 times of the material thickness of the flat material.
With these groove depths, the static characteristics of the hollow
profile are maintained to a most possible extent, while a
predetermined guidance of a connection part on the hollow profile
is insured.
Advantageously, at least one groove is provided on each of the
walls of a hollow profile. On a wall of a hollow profile, several
grooves can be formed next to each other. Preferably, all of the
grooves have the same profile, i.e., the same depth and the same
width. With an inventive hollow profile designed for use in an
assembly system, with grooves having the same profile or shape, a
greater flexibility in the use of the hollow profile is
obtained.
The bottom of the at least one groove extends preferably parallel
to a corresponding axis of the hollow profile. With a rectangular
hollow profile having four side walls with a groove formed in each
of the side walls the grooves bottom extend parallel to respective
axes of the hollow profile. The grooves extend, preferably, along
the entire length of the profile parallel to respective axes.
Advantageously, at least one mounting opening is formed in the
bottom of the at least one groove. The mounting opening(s) is (are)
designed for receiving fastening means for securing a connection
element on the hollow profile. The mounting opening advantageously
is adapted to the type of the fastening means, and the opening can
have, e.g., a round or rectangular cross-section.
Preferably, the flat material for forming the inventive hollow
profile is a sheet metal that, preferably, is subjected to a
rolling and bending process in order to obtain the profile. Flat
material in form of sheet metal is treated easily and economically.
By using a rolling/bending process, a plurality of different
profiles can be formed.
In addition to the rolling/bending process, other processes, e.g.,
a stamping/bending process, can be used.
A method of forming an inventive hollow profile formed of a flat
material and including a least one groove provided on an outer side
of at least one wall of the hollow profile and having a bottom
spaced from the outer side by depth and two opposite side walls,
includes the steps of: forming a groove with a depth greater than a
predetermined end depth of the at least one groove; pressing a
bottom of the groove with the greater depth in a direction opposite
a direction of formation of the groove with the greater depth until
the predetermined end depth of the at least one groove is
substantially reached, with formation, as a result of a groove
having a dovetail cross-section; pressing a projecting material of
the dovetail groove backward, and bending the flat material to a
desired shape of the profile.
Because the groove depth obtained in the first step is greater than
the predetermined end depth of the at least one groove, the inner
bending radius can correspond to the thickness of the flat
material. Therefore, the material strength of the flat material in
the bending region is reduced only slightly. Then, the groove
bottom is pressed in a direction opposite the groove formation
direction until the predetermined depth is reached. With this step,
a dovetail cross-section is formed in the groove. The width of the
groove in the plane of a respective side wall of the groove is
smaller than the predetermined width of the finished groove. The
projecting, in the cross-section, material is then pressed sidewise
backward, and after this step, the groove has a desired width. Upon
pressing back the projecting material, the material can flow in a
free space in the region of the inner radius. As a result of flow
of the material, statically favorable material strength and
material accumulation are obtained in regions that are subjected,
under load, to greatest negative stresses. Finally, the flat
material is bent to a predetermined profile. Preferably, the
operational steps for forming a groove are parts of a rolling
process.
The loading of the material takes place not by superimposition of
stresses in the main bending region, but is rather displaced to the
side walls. There, the stresses can be distributed relatively free,
so that the material would not be damaged in this region. Besides,
despite the small groove depth, the side groove walls, which have
substantially the same width and height and serve as longitudinal
and lateral guides for a connection part the shape of which is
matched to that of the groove, extend perpendicular to the groove
bottom.
Preferably after pressing backward the projecting, in the
cross-section of the groove, material, in a further step, the
groove bottom is straightened. Dependent on the construction of the
device for forming the groove, during different operational steps,
large deviations of the groove dimensions, which lie outside of
predetermined tolerances, takes place. With straightening of the
groove bottom, the tolerances are limited to acceptable values.
According to an alternative method of forming the groove, the
groove is supported, during the backward pressing of the projecting
material, sidewise and beneath, e.g., by rolls or other supports,
which permits to eliminate the secondary straightening of the
groove bottom.
Advantageously, the method includes the step of material locking
connection of the free longitudinal edges of the bent flat
material, which finishes the formation of the inventive hollow
profile. Advantageously, the longitudinal edges are connected with
each other along their entire length, e.g., are butt-welded,
soldered, or glued with each other.
The novel features of the present invention, which are considered
as characteristics for the invention, are set forth in the appended
claims. The invention itself, however both as to its construction
and its mode operation, together with additional advantages and
objects thereof, will be best understood from the following
detailed description of preferred embodiments, when read with
reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawing show:
FIG. 1 a cross-sectional view of a hollow profile according to the
present invention;
FIG. 2 a detail view of a groove at an increased, in comparison
with FIG. 1 scale, shown in region II in FIG. 1;
FIG. 3 a cross-sectional view of the inventive hollow profile with
mounted thereon connection parts; and
FIG. 4a 4c steps illustrating formation of a groove according to
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A hollow profile 1 according to the present invention, which is
shown in FIG. 1, has a substantially rectangular cross-section, a
first pair of side walls 2.1 and 2.2 which extend parallel to each
other and to one of the axes 3 of the cross-section of the profile
1, and a second pair of side walls 5.1 and 5.2 which also extend
parallel to each other and to another of the axes 4 of the
cross-section of the profile 1. In the embodiment shown in FIG. 1,
the hollow profile 1 has a smaller dimension in the direction of
the axis 3 than in the direction of the axis 4. The hollow profile
1 is formed of sheet steel by rolling/bending process, and it has a
uniform thickness d. The treated and profiled sheet steel has its
opposite end surfaces connected by a butt-joined weld 10, forming a
hollow profile 1.
On the side walls 2.1 and 2.2, there are formed, respectively,
grooves 6.1 and 6.2 extending in the longitudinal direction L, and
on the side walls 5.1 and 5.2, there are formed, respectively,
grooves 7.1 and 7.2 likewise extending in the longitudinal
direction L of the hollow profile 1. The grooves 6.1, 6.2 and 7.1,
7.2 form longitudinal and lateral guide means for shaped and
connection parts matching the groove arrangement. The grooves 6.1,
6.2, 7.1, and 7.2 have all the same width b and depth t. This
provides for arrangement in the grooves 6.1, 6.2, 7.1, and 7.2 of
the matching connection parts along the entire longitudinal
direction L of the hollow profile and in each of the side walls
2.1, 2.2, 5.1, and 5.2. The layout of grooves 6.1, 6.2, 7.1 and 7.2
permits to use a large area of the hollow profile when the hollow
profile is used, e.g., as an assembly support in an assembly
system. Each of the grooves 6.1, 6.2, 7.1, and 7.2 has a bottom
8.1, 8.2, 9.1, and 9.2, respectively, and a pair of side walls 13.1
and 13.2.
The bottoms 8.1 and 8.2 of the grooves 6.1 and 6.2 extend parallel
to planes of respective side wall 2.1 and 2.2. The bottoms 9.1 and
9.2 of the grooves 7.1 and 7.2 extend parallel to planes of
respective side walls 5.1 and 5.2. A mounting opening 11.1, 11.2,
through which a fastening element can extend, is formed in a
respective groove bottom 8.1, 8.2 in the region of intersection of
the axis 4 with the respective bottom 8.1, 8.2. The mounting
openings 11.1, 11.2 extend along the axis 4. In groove bottom 9.1
and 9.2 in the region of intersection of the axis 3 with respective
bottom 9.1, 9.2, there are provided, respectively, mounting
openings 12.1, 12.2 through which a fastening element can extend.
The mounting openings 12.1, 12.2 extend along the axis 3.
FIG. 2 shows, at an increased scale, a detail of groove 13.1 in the
region II in FIG. 1. The deptht of the groove 7.2 corresponds
approximately to 1.2 times of the thickness d of the sheet steel
the hollow profile 1 is made of. The side wall 13.1 extends
substantially perpendicular to the groove bottom 9.2 and has a flat
or even section h the height of which amounts to about 70% of the
depth t. A connection part, which is arrangeable in the groove 7.2,
can be guided in the longitudinal direction L of the hollow profile
1 and in the direction of side walls 13.1 and 13.2.
A cross-sectional view of the hollow profile 1 shown in FIG. 1,
together with respective connection parts received in respective
grooves 6.1, 6.2, 7.1, and 7.2, is shown in FIG. 3. In the groove
6.1 in the side wall 2.1, there is arranged a first connection part
which is formed as an angle 21. The width W of the angle 21 is
minimally smaller than the width b of the groove 6.1. The angle 21
is guided along the side wall 2.1 parallel to the plane of the side
wall 2.1 along the groove side walls 13.1 and 13.2. The angle 21 is
secured to the hollow profile 1 with a head bolt 22.
A second connection part, an angle 26, is arranged in the groove
7.2 in the side wall 5.2. The angle 26 has a width V which is
greater than the width b of the groove 7.2. A leg 27 of the angle
27, which provides for mounting of the angle 26 on the hollow
profile 1, has a shape complementary to the shape of the groove
7.2. The angle 26 is secured to the hollow profile 1 with a head
bolt 28. Because the groove 7.2 has, as other grooves of the hollow
profile 1, its side walls extending substantially perpendicular to
the bottom, the leg 27 of the angle 26 contacts the side walls of
the groove 7.2 along its entire surface. With a sidewise loading of
the angle 26, e.g., in direction of arrow 29, there are no any
essential force components that could lift the angle 26 off the
groove 7.2. Moreover, due to the flat contact of the angle 26 with
side walls 13.1 and 13.2 of the groove 7.2 or of the angle 21 with
the side walls 13.1, 13.2 of the groove 6.1, a respective side wall
can absorb a high side force component.
FIGS. 4a 4c show the method of forming a groove in the hollow
profile 1. Below, a rolling process of forming a groove of the
hollow profile will be discussed. First, in a flat material 31,
e.g., sheet steel, with a roll (not shown), a groove 32 having a
depth T is formed. The depth T is larger than the predetermined end
depth t which the finished groove 32 should have. The inner bending
radii R.sub.1 and R.sub.2 approximately correspond to the thickness
d of the flat material 31.
Then, a groove bottom 33 is pressed in a direction apposite the
direction of forming the groove, e.g., in the direction shown with
arrow 34, until the groove 32 has a desired end depth t. With such
a process, upon having been formed, the groove 32 has a dovetail
cross-section. The inner with U of the groove 32 during this
process is smaller than the width d that the groove 32 should have
at the end of the manufacturing process.
With a first sizing roll 35, the projecting material 36 is pressed
back, which causes flow of material with resulting compacting of
the material. Subsequently or during pressing back of the
projecting material 36, the groove bottom 33 is straightened with a
dressing roll 37. In addition, a second sizing roll 38 can be used
for pressing back projecting material 39 in a sidewise direction,
whereby, in this region also the material is compacted and the
material hardness increases.
The finished groove 32, which is formed according to the inventive
method, is provided with even or flat sections which occupy a large
portion of respective side walls 40.1, 40.2 of the groove 32 and
which extend substantially perpendicular to the groove bottom
33.
In summary, there is provided according to the invention, a hollow
profile formed of a flat material and having, despite formation of
grooves, high static characteristics. Despite a small depth of the
grooves, an adequate longitudinal and lateral guidance of
connection parts, which are to be mounted on the profile, in the
grooves is insured. The profile can be economically produced and
has a small weight.
Though the present invention was shown and described with
references to the preferred embodiment, such is merely illustrative
of the present invention and is not to be construed as a limitation
thereof and various modifications of the present invention will be
apparent to those skilled in the art. It is therefore not intended
that the present invention be limited to the disclosed embodiment
or details thereof, and the present invention includes all
variations and/or alternative embodiments within the spirit and
scope of the present invention as defined by the appended
claims.
* * * * *